Whereas EAS tags are typically of a "passive" type, i.e., do not carry therewith a source of power, but rather respond to incident energy to reradiate the same or a permutation thereof, there are known EAS tags which are of "active" type, carrying therewith a battery or like source of electrical power. Advantage attends the on-board, self-powering capacity, since the tag can thereby be of the so-called "smart" or "intelligent" variety, such as is disclosed in commonly-assigned U.S. Pat. No. 4,686,513, which is incorporated herein by this reference thereto.
The tag of the '513 patent, by reason of its on-board power supply, has capacity for processing coded, received messages to assume responsive diverse states and to exhibit different operational characteristics corresponding with such states, thereby expanding the operational states of the tag as contrasted with the passive-type tags.
One concern attending active tags is that of power source conservation and measures are known to address this concern. A version of commercial tag of the common assignee, Sensormatic Electronics Corporation, included, as a part of the printed circuit board (PCB), which incorporates circuitry related to received message decoding and tag state assignment, electrically conductive traces adapted to be interconnected by movement of an electrically conductive member upon tag orientation change. Thus, one of the states of the '513 patent tag is "Sleep", wherein its circuitry is dormant, conserving battery life. On movement of the article to which the tag is attached, the intention of the commercial tag under discussion was to "re-awaken" on interconnection of the electrical traces by movement of the electrically conductive member. To the extent that movement of the tag did not insure certainty of such trace interconnections, this prior art arrangement was not as effective as desired in preserving power source integrity while at the same time re-awakening tags, i.e., rendering the tag electrical circuitry active.
In commonly-assigned and copending application Ser. No. 507,655, entitled "EAS Tag with Motion Detection Facility" and filed on Apr. 10, 1990, which has issued as U.S. Pat. No. 5,025,246 Jun. 18, 1991, an EAS tag of improved character is disclosed. In that application, there is provided:
(a) an EAS tag inclusive of an electrical power source contained with the tag and circuitry powered by the electrical power source; and
(b) a motion sensor operatively associated with the tag and contained therewith, the motion sensor providing output indication of movement and thereupon effecting loading of the electrical power source by such tag circuitry.
The motion sensor comprises first and second housings of electrically conductive material, first and second electrically conductive elements movably supported respectively in the first and second housings, and a joinder member for mechanical interconnection of the first and second housings, the joinder member being comprised of electrically insulative material to electrically isolate the housings from one another and defining a passage permitting movement of the first and second electrically conductive means between the first and second housings responsively to orientation of the sensor or apparatus carrying the same.
The joinder member, the housings and the first and second electrically conductive elements are collectively dimensioned to provide for electrical conductivity between the first and second housings upon reorientation of the tag from a disposition wherein neither of the first and second electrically conductive elements is in registry with the joinder member to other disposition.
While the first-noted and commonly-assigned approach has disadvantages as above noted, the second-noted and commonly-assigned approach is effective in its certainty of detection of tag movement, but has some disadvantage in its cost and complexity. From applicant's viewpoint, need for improvement exists both in lessening cost and in simplifying structure and is herein addressed.